I have 6 Catalyst 3750 switches in stacked configuration running IOS version 12.1(19) EA1.
I need to know if EtherChannel can be configured between ports from different switches. It took the configuration, For example, here is the config
interface Port-channel1
switchport trunk encapsulation isl
switchport trunk allowed vlan 2-4,9,254
switchport mode trunk
no ip addres
interface GigabitEthernet1/0/1
switchport trunk encapsulation isl
switchport trunk allowed vlan 2-4,9,254
switchport mode trunk
no ip address
channel-group 1 mode on
interface GigabitEthernet2/0/1
switchport trunk encapsulation isl
switchport trunk allowed vlan 2-4,9,254
switchport mode trunk
no ip address
shutdown
channel-group 1 mode on,
-----------------------------------------------
Now, observe the Spanning Tree outputs on port-channel, gig 1/0/1, and 2/0/1
show spanning-tree interface port-channel 1
Vlan Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------
VLAN0002 Root FWD 3 128.472 P2p
VLAN0003 Root FWD 3 128.472 P2p
VLAN0004 Root FWD 3 128.472 P2p
VLAN0009 Root FWD 3 128.472 P2p
VLAN0254 Root FWD 3 128.472 P2p
show spanning-tree interface gigabitEthernet 1/0/1
Vlan Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------
VLAN0002 Root FWD 3 128.472 P2p
VLAN0003 Root FWD 3 128.472 P2p
VLAN0004 Root FWD 3 128.472 P2p
VLAN0009 Root FWD 3 128.472 P2p
VLAN0254 Root FWD 3 128.472 P2p
show spanning-tree interface gigabitEthernet 2/0/1
no spanning tree info available for GigabitEthernet2/0/1
Why int gig 2/0/1 wouldn't give any info on spanning-tree. Really Wierd.
Any idea?
Thanks,
